It is known that a cover for an outdoor swimming pool generally keeps the pool cleaner than an uncovered pool. Also, translucent or transparent pool covers tend to permit the sun's rays to enter the water, heating the same. Covers, furthermore, tend to reduce evaporation and conserve the latent heat in the water. Thus, pool covers are beneficial. A number of pool covers are available, but they are usually custom made, and are rather expensive. Being exposed to the weather, particularly the sun, the covers do not have a long life.
Priorly, a number of patents have shown various types of custom pool covers. For example, U.S. Pat. No. 3,600,721 to Pusey of Aug. 24, 1971 shows a pool cover formed of a plastic film cut to the shape of the water surface. The cover is made flotable by securing to the sheet periphery air inflatable tubes, usually of the same material as the cover film. The tubes are usually welded to the edge, or the edge may be folded back on itself and welded to form airtight tubes. The manufacture of the cover is a custom job, requiring special equipment to form the tubes and weld the tubes to the plastic film.
U.S. Pat. No. 3,940,809 to Huges, dated Mar. 2, 1976, also, uses an air filled, endless plastic loop around the pool cover material. This again requires a custom made cover with special tools and equipment.
A cover larger than the pool is shown in U.S. Pat. No. 3,732,581 to Petti of May 15, 1973, using elongated water bags secured to the edge of the plastic material of the cover, which is larger than the pool surface.
A series of unconnected, small discs are shown in U.S. Pat. No. 3,984,882, providing a series of small, individual solar panels. These panels do not and can not cover the entire surface as they are round and in abutting position leave a substantial surface area uncovered.
French Pat. No. 660,246 of Feb. 25, 1965 shows a series of rigid panels interconnected so that fold up in an accordian fold. The rigid panels cover the pool surface, but obviously must be custom made.